<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        .box1{
            width: 300px;
            height: 200px;
            background: pink;
        }
        /* .box2{
            width: 300px;
            height: 100px;
            background: skyblue;
            padding: 10px;
            border: 5px solid #000;
            margin: 10px;
        } */
         .box2{
            /* width: 300px; */
            height: 100px;
            background: skyblue;
            padding: 10px;
            margin: 10px;
            border: 5px solid #000
         }
    </style>
</head>
<body>
    <div class="box1">
        <div class="box2">盒子的内容</div>
    </div>
</body>
</html>